hsc function use as zero speed sw

hi,
i'm not too familar with the hsc function of micrologix 1500
proceesor type 1764-lrp with base unit 1764-24bwa.what i need to
accomplish is to energize a relay when an encoder rpm (very low rpm
above 1 to 5 rpm) to energize a relay and deenergize the relay below the preset rpm(1 to 5).this relay will be energize in forward
and reverse direction.can you make me a program to do this job.
your help will be appreciated.

thanks,
senen

The best you can do is go to www.ab.com and download a code example of an hsc application similar to the one you´re trying to set up and then you can learn by yourself.

By the way 1 to 5 rpm is not a high speed so you can do it with a timer an a counter trying to catch how many detections occur in one minute.

good luck

hi,
the machine will run at 1600 fpm(encoder rpm not determine yet).we have a unit we call sparker which is use for detecting pin holes in a wire and this sparker is set around 8 kv (very low ma).that is why we need a zero speed sw that will turn on this sparker only when the line start moving and turn off when the line is stopped.before we use a digital to analog converter to activate a voltage sensing relay to turn on the sparker but we are not using plc.now since we are using plc which is capable of doing the same task with less hardware involve.

thanks,
senen

Peter Nachtwey said:

Why not turn on the 'sparker' only when the motor that moves the line is turned on.

Click to expand...

Peter,

Motor may be turned on, but it may not be moving physically, so I think some sort of speed switch is necessary.

I hope, I understood the problem correctly, correct me,if need be.

thanks and regards,
ali